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[netCDF #LWL-894598]: Netcdf4 documentation for Fortran 90 (parallel IO)

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  • Subject: [netCDF #LWL-894598]: Netcdf4 documentation for Fortran 90 (parallel IO)
  • Date: Tue, 07 Apr 2009 12:42:14 -0600
> Hello,
>
> Thanks for this. I now have a trickier question (I can create a new
> question if you'd prefer).
>
> We need to be able to generate really large files (64-bit), and I'd also
> like to generate them in "classic" format. This is because I need to
> generate files that standard tools can read. Please correct me if I'm
> wrong, but the documentation I found says that neither classic or 64-bit
> can be used in netcdf 4 calls (create or open) for parallel IO.
>
> Here is the statement I found:
>
> NetCDF-4 provides access to HDF5 parallel I/O features for netCDF-4/HDF5
> files. NetCDF classic and 64-bit offset format may not be opened or
> created for use with parallel I/O. (They may be opened and created, but
> parallel I/O is not available.)
>
> If this is the case, I think netcdf 4 won't work for us.
>
> Annette
>


You are correct. If you use classic format or 64-bit offset format then you
cannot use parallel I/O with netCDF.

*Unless* you use the pnetcdf package. This is not a unidata package, and it
uses a different (but similar) API. It allows parallel I/O for classic and
64-bit offset files (but doesn't handle netCDF-4 files).

Please let me know if this is not clear...

Thanks,

Ed

Ticket Details
===================
Ticket ID: LWL-894598
Department: Support netCDF
Priority: Normal
Status: Closed